# man vxassist
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Maintenance Commands vxassist(1M)
NAME
vxassist - create, relayout, convert, mirror, backup, grow,
shrink, delete, and move volumes
SYNOPSIS
vxassist [ options ] [ -b ] addlog volume [ attribute ... ]
vxassist [ options ] [ -b ] convert volume [ attribute ... ]
vxassist [ options ] [ -b ] growby volume lengthchange [
attribute ... ]
vxassist [ options ] [ -b ] growto volume newlength [ attri-
bute ... ]
vxassist help [ alloc | attrs | layout | mirror | options |
showattrs | space | usage]
vxassist [ options ] [ -b ] make volume length [ attribute
... ]
vxassist [ options ] [ -b ] maxsize [ attribute ... ]
vxassist [ options ] [ -b ] maxgrow volume [ attribute ... ]
vxassist [ options ] [ -b ] mirror volume [ attribute ... ]
vxassist [ options ] [ -b ] move volume storage-spec ... [
attribute ... ]
vxassist [ options ] [ -b ] relayout volume [ attribute ...
]
vxassist [ options ] remove {volume|mirror|log } volume
storage-spec ... [ attribute ... ]
vxassist [ options ] shrinkby volume lengthchange
vxassist [ options ] shrinkto volume newlength
vxassist [ options ] snapabort volume
vxassist [ options ] snapshot volume newvolume
vxassist [ options ] [ -b ] snapstart volume [ attribute ...
]
vxassist [ options ] snapwait volume
DESCRIPTION
The vxassist utility is an interface to the VERITAS Volume
Manager that finds space for and creates volumes, performs
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volume conversion, adds mirrors and logs to existing
volumes, extends and shrinks existing volumes, provides for
the migration of data from a specified set of disks, and
provides facilities for the on-line backup of existing
volumes.
The vxassist command is supplied a keyword that selects the
action to be performed.
Each operation can be applied to only one disk group at a
time, due to internal implementation constraints. For the
make operation, attributes that name specific disks may be
used to determine a default disk group, according to the
standard disk group selection rules described in
vxintro(1M). For other operations, the volume operand is
used. A specific disk group can be forced with -g disk-
group. When no disk attributes are specified, the make
operation defaults to using the rootdg disk group. An
alternate default disk group can be specified in a defaults
file (/etc/default/vxassist).
Many vxassist operations can take a set of attributes that
specify how volumes should be laid out, which sets of disks
they should be built on, among other things. Attributes are
of two basic types: storage specifications, and attribute
settings. Storage specification attributes are either sim-
ple disk names (for example, disk01) or selected groups of
disks (for example, ctlr:c1 specifies all disks on con-
troller 1). Excluded (negated) storage specification can be
specified with a prefix of !. For example, the arguments
ctlr:c1 and !target:c1t5 can be combined to indicate that
storage should be allocated from controller 1, but not from
SCSI target 5 on that controller.
Other attributes are of the form attrname=value; these addi-
tional attributes can specify the type of a volume (mir-
rored, RAID-5, striped, logged), layout policies (contigu-
ous, spanning), mirroring requirements (mirror across con-
trollers or SCSI targets), constraint parameters (constrain
allocations to a single controller), and more. A complete
list of attribute specifications is given later in this man
page.
If no non-excluded storage specification attributes are
given, then any non-reserved, non-volatile, non-spare, non-
excluded disk may be used to allocate storage. Attributes
may constrain the selection, particularly with respect to
the selection of multiple disks. For example, the command:
vxassist make mirvol 500m layout=mirror,log mirror=ctlr !ctlr:c2
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requests that vxassist create a new mirrored volume on any
disks that are not on controller 2. The selection of disks
is constrained by the mirror=ctlr attribute such that no
disks within a mirror can be on the same controller as any
disks on the other mirror.
KEYWORDS
addlog Add a log to a mirrored or RAID-5 volume. A log
can be added to a mirrored volume only if the log-
ging type of the volume is DRL (this is the
default logging type). When adding the first log
to a mirrored or RAID-5 volume, the loglen attri-
bute can be used to specify the length of the log;
otherwise, the loglen attribute will be ignored.
Other attributes can be specified to indicate
desired properties for the new allocations. Mir-
roring constraints do not apply to logs, though
storage constraints can be specified that con-
strain the logs to disk sets already used by the
volume.
Adding a log to a DRL mirrored volume involves
creating a single log subdisk and a new plex to
contain that subdisk. The new plex will then be
attached to the volume. Adding a log to a RAID-5
volume involves creating a new plex that will be
attached to the volume as a log plex.
convert Converts a volume layout to a mirror-stripe from a
stripe-mirror, or from a mirror-stripe to a
stripe-mirror. Also converts to mirror-concat from
a concat-mirror, or from a mirror-concat to a
concat-mirror.
growby | growto
Increase the length of the named volume to the
length specified by newlength (growto), or by the
length specified by lengthchange (growby). The
new length or change in length is specified as a
standard Volume Manager length (see vxintro(1M)).
The growto operation fails if the new length is
not greater than the current volume length. The
length of the volume is increased by extending
existing subdisks in the volume, or by adding and
associating new subdisks. Plexes that are not
fully populated already (that is, that are sparse)
are left unchanged. Log-only plexes are also left
unchanged.
When a volume is grown, the volume may be con-
verted from one layout to another as a side
effect. For example, a volume that has the
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mirror-stripe layout may be converted to stripe-
mirror when it is grown. This kind of conversion
is done if vxassist determines that the new volume
is too small or large for the original layout. If
the new volume layout is inappropriate, the volume
can be converted back using the vxassist convert
command. See Layout Specifications for a descrip-
tion of the methods used to determine disk lay-
outs.
Attributes can be specified to indicate various
desired properties for the new allocations. Any
mirroring constraints will still apply between all
extensions to the existing mirrors and the other
mirrors. Growing of a volume requires that the
volume be enabled.
No attempt will be made by vxassist to adapt the
file system that resides on the volume (or other
users of the volume). It is expected that any
necessary application notifications will be made
after the grow operation completes successfully.
help Displays information on vxassist usage and VxVM
attributes.
make Create a volume with the specified name and the
specified length. The length is specified as a
standard Volume Manager length (see vxintro(1M)).
Attributes can be specified to indicate various
desired properties and storage locations for the
created volume. See Layout Specifications for a
description of the methods used to determine disk
layouts.
maxgrow Reports the maximum size a volume could grow given
its attributes and given the free storage avail-
able.
maxsize Reports the maximum size a volume could be created
with given the attributes specified and given the
free storage available.
mirror Create a new mirror (or plex) and attach it to the
volume. This operation is allowed only if the
volume is enabled. Attributes can be specified to
indicate various desired properties and storage
locations for the created volume. Attributes that
constrain mirroring (such as requiring that mir-
rors be on separate groups of disks) apply between
the existing mirrors of the volume and the new
mirror.
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move Move subdisks within the named volume off the
excluded storage specified on the command line.
Excluded storage is specified with a prefix of !.
The move operation requires that at least one
excluded storage specification be given.
If the volume is enabled, then subdisks within
detached or disabled plexes (or detached log or
RAID-5 subdisks) will be moved without recovery of
data. If the volume is not enabled, then stale
log or RAID-5 subdisks, or subdisks within STALE
or OFFLINE plexes, will be moved without recovery;
if there are other subdisks within a non-enabled
volume that require moving, then the move opera-
tion will fail.
For enabled subdisks in enabled plexes within an
enabled volume, the data within subdisks will be
moved to the new location, without loss of availa-
bility (or redundancy) of the volume.
relayout Change a volume layout or properties. This opera-
tion changes the number of columns in a stripe or
the stripe width of a volume. It also converts a
volume to or from RAID-5, mirrored, concat-
mirrored, striped, or any similar layout.
During the relayout process, a volume may also be
converted into an intermediate layout. For exam-
ple, to convert from a 4-column mirror-stripe to a
5-column mirror-stripe, the volume is first
changed to a stripe-mirror before the new column
is added.
To change volume vol1 from a 4-column mirror-
stripe to a 5-column mirror-stripe, enter:
vxassist relayout vol1 ncol=5
vxassist convert vol1 layout=mirror-stripe
To change volume vol1 from a 4-column stripe-
mirror to a 5-column stripe-mirror, enter:
vxassist relayout vol1 ncol=5
If you view the volume with vxprint during this
layout conversion, the volume shows several subvo-
lumes that are used during the change, and a more
complex configuration than usual.
After the new column is added the volume remains
in the stripe-mirror layout. You must use
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vxassist convert to convert back to a mirror-
stripe layout.
Note: If the system crashes during a relayout
operation, the process continues. However, if the
relayout was a two-stage operation, you must run a
vxassist convert command to convert back to the
original layout.
remove Depending on the next keyword (volume, mirror, or
log), vxassist deletes the entire volume, one or
more mirrors, or one or more logs. When deleting a
mirror or a log, the storage to be removed can be
specified with the ! attribute. The alloc=, nmir-
ror=, and nlog= are also used to determine the
number of mirrors or logs to remove. When the
number of mirrors drops to 1, logs are also
removed. By default, vxassist removes 1 mirror or
1 log.
shrinkby | shrinkto
Decrease the length of the named volume to the
length specified by newlength (shrinkto), or by
the length specified by lengthchange (shrinkby).
The new length or change in length is specified as
a standard Volume Manager length (see
vxintro(1M)). The shrinkto operation fails if the
new length is not less than the current volume
length.
The length of a volume is decreased by removing
and shortening subdisks to leave each plex with
the desired volume length. The freed space can
then be allocated for use by other volumes.
Log-only plexes are left unchanged.
When a volume is shrunk, the volume may be con-
verted from one layout to another as a side
effect. For example, a volume that has the
mirror-stripe layout may be converted to stripe-
mirror when it is shrunk. This kind of conversion
is done if vxassist determines that the new volume
is too small or large for the original layout. If
the new volume layout is inappropriate, the volume
can be converted back using the vxassist convert
command. See Layout Specifications for a descrip-
tion of the methods used to determine disk lay-
outs.
No attempt will be made by vxassist to adapt the
file system that resides on the volume (or other
users of the volume). It is expected that any
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necessary application notifications will be made
before the shrink operation is initiated.
snapabort When a snapstart mirror has been started (and
eventually completed), the snapabort can be used
to remove the mirror snapshot.
snapstart and snapshot
Create a temporary mirror and attach it to the
named volume. When the attach completes, the mir-
ror will be considered a candidate for selection
by the snapshot operation. The snapshot operation
takes one of these attached temporary mirrors and
creates a new volume with the temporary mirror as
its one plex. Attributes can be specified to
indicate desired properties of the snapshot mir-
ror.
Some usage types will attempt to synchronize any
in-memory data associated with the volume (such as
unwritten file system modifications) when the
snapshot operation is done. In particular, if the
fsgen usage type is used with a volume containing
a VxFS file system, then cooperating procedures
ensure that all file system data is consistently
flushed to the volume. For ufs and s5, the syn-
chronization operation consists of a call to sync,
which will make the snapshot a better image, but
which may leave some inconsistencies between in-
memory file system data and the data residing on
the backup image.
snapwait If a snapstart mirror attach is done as a back-
ground task (such as using the -b option), it may
be convenient to wait for an attached mirror to
become available. The snapwait operation waits
for such an attach to complete on the named
volume. When a snapshot attach has completed, the
operation exits.
OPTIONS
-b Perform extended operations in the background.
This applies to plex consistency recovery opera-
tions for vxassist make, growto, and growby. This
flag also applies to plex attach operations
started by vxassist mirror, vxassist snapstart,
and to Relayout operations started by vxassist
Relayout.
-d defaults
Specify a file containing defaults for various
attributes related to volume creation and space
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allocation. If not specified, this defaults to
/etc/default/vxassist.
-f Forces operations not usually allowed by vxassist.
-g diskgroup
Specify the disk group for the operation, either
by disk group ID or by disk group name. By
default, the disk group is chosen based on the
medianame operands (if any) for the vxassist make
operation, or based on the volume operands for all
other operations.
-n Do not read the system defaults file.
-o useopt Pass in usage-type-specific options to the opera-
tion. A certain set of operations are expected to
be implemented by all usage types:
slow[=iodelay]
Reduce the system performance impact of
copy operations. Copy and plex con-
sistency recovery operations are usually
a set of short operations on small
regions of the volume (normally from 16
kilobytes to 128 kilobytes). This
option inserts a delay between the
recovery of each such region. A
specific delay can be specified with
iodelay as a number of milliseconds, or
a default is chosen (normally 250 mil-
liseconds).
iosize=size
Perform copy and recovery operations in
regions with the length specified by
size, which is a standard Volume Manager
length number (see vxintro(1M)). Speci-
fying a larger number typically causes
the operation to complete sooner, but
with greater impact on other processes
using the volume. The default I/O size
is typically between 32 and 128 kilo-
bytes.
-p For use with maxsize and maxgrow. Prints only the
maximum size with no text wrappers.
-r Tells vxassist to include the spare disks (the
disks reserved for relocation) in the calculation.
-t tasktag
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If any tasks are registered to track the progress
of an operation, mark them with the tag tasktag.
This option is passed to utilities called by vxas-
sist, so any child tasks are also tagged with
tasktag.
-U usetype
Limit the operation to apply to this usage type.
Attempts to affect volumes with a different usage
type will fail. For a vxassist make operation,
this indicates the usage type to use for the
created volume. Otherwise, the default is used
and is determined by the existence of an entry in
the /etc/default/vxassist file or else is set to
the fsgen usage type.
-v Traces calls to other utilities to determine which
VxVM commands vxassist is executing.
ATTRIBUTES
Attribute values for various purposes can be specified with
arguments of the form attribute=value. Attributes can also
be passed in through a defaults file. Default attribute
values can be stored in the file /etc/default/vxassist.
Attributes are selected according to the order in which they
are scanned. In general they are taken in decreasing prior-
ity of being specified on:
1. The command line.
2. The specified defaults file (as supplied with the -d
command line argument).
3. The system defaults file (as specified in
/etc/default/vxassist).
Attributes from all sources have the same form. However, in
some cases, command-line attributes change default behaviors
in ways that defaults-file supplied attributes do not. In
particular, references to mirroring (such as specifying a
mirror count) or logging (such as specifying a log count or
length) on the command line will cause mirroring or logging
to happen by default. If such attributes are specified in a
defaults file, then they just indicate the attributes that
would be used if mirroring or logging were enabled.
Attributes are either storage specifications (possibly
negated), or are in the form attribute=value. In a defaults
file, attributes are whitespace separated or are on separate
lines. Blank lines in a defaults file are ignored, and com-
ments can be included with the standard # convention.
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Storage Specifications
Storage specification attributes have one of the following
forms:
[!]diskname
Specify (or exclude) the given disk. diskname
refers to a disk media record name in a Volume
Manager disk group.
[!]diskclass:instance
Specify (or exclude) a set of disks. diskclass
names a particular type of disk grouping (for
example, ctlr to indicate groups of disks on a
single controller), and instance specifies which
grouping of that type (for example c1). Each type
of disk class has a particular format for specify-
ing instances of the class.
diskclass:same
Specify that the allocation must be constrained to
include disks from the same instance of the given
class. For example, a storage specification of
diskparam:same indicates that all disks selected
must have the same basic parameters (tracksize,
cylinder size, size, and revolutions-per-minute),
but does not specify which specific parameters to
use.
The defined disk classes (and alternate names, or aliases,
for those classes) are as follows:
ctlr (alias c, ctrl, cntrl, controller)
Specify disks from a particular controller. The
controller is identified in the form c#, where #
is a decimal controller number starting at 0.
ctype (alias ctlrtype, ctrltype, controllertype)
Specify disks from a particular type of con-
troller. The controller type is usually a driver
name. For example, on Sun machines, the regular
SCSI controller type can be identified as
ctype:esp. As a special case, the SPARCstorage
Array controller type is specified as ctype:ssa.
da Specify a specific Volume Manager disk by disk
access record name. An example of a disk access
record name is c2t1d0s2, which indicates a spe-
cial Volume Manager disk defined on slice 2 of
c2t1d0s2.
device (alias d)
Specify all Volume Manager disks on a specific
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physical disk. The physical disk is specified in
the form c#t#d#, which indicates the controller,
target, and disk numbers. Normally, only one
Volume Manager disk device is created for each
physical disk. However, the vxdisk define opera-
tion (see vxdisk(1M)) can be used to create addi-
tional Volume Manager disk devices on selected
partitions.
fied
Specify disks with a particular geometry. The geometry is speci-
in the form cyls.heads.sectors, to indicate the
number of cylinders, heads, and sectors per track,
of the disk. Many modern drives have variable
geometries (or geometries that don't fit the stan-
dard conventions). For such drives, the geometry
parameters used are whatever the drive reports.
diskparam Specify disks with particular parameters. The
parameters are specified in the form
cyls.heads.sectors.rpm, to indicate cylinders,
heads, sectors per track, and the number of revo-
lutions per minute of the drive. As with the
diskgeom parameter, the instances of the diskparam
disk class depend upon the values reported by the
drive, and may not be accurate.
diskrpm (alias rpm)
Specify disks with a particular number of revolu-
tions per minute. The revolutions per minute is
given as a simple decimal number.
dm (alias disk)
Specify a Volume Manager disk by disk media record
name, in the disk group of the volume. Specifying
a disk class type of dm or disk is equivalent to
giving a storage specification with no disk class
name.
probe_granularity
The granularity is a result of the maxsize
request. The default value is 1M.
target (alias t)
Specify disks on the same SCSI target address in
the same controller. The target is specified in
the form c#t#. For example, t:c2t4 selects disks
on target 4 of controller 2.
tray Specify disks in the same removable tray (for
SPARCstorage Array controllers). Trays in the
SPARCstorage Array are grouped as two SCSI targets
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per tray (for example, targets 0 and 1 are in the
same tray). Trays are specified in the form
c#tray#, where c# identifies a particular
SPARCstorage Array controller and tray# is the
number of a tray (0 for SCSI targets 0 and 1, 1
for targets 2 and 3, or 2 for targets 4 and 5).
For example, c2tray2 selects disks in tray 2 (tar-
gets 4 and 5) of controller 2.
The diskgeom and diskparam attributes are most often useful
in the form diskgeom:same and diskparam:same, to indicate
that all disks used for creating a volume should be on simi-
lar disk drives.
Other Attributes
Other attributes are of the form attribute=value. The attri-
bute name in an attribute value pair will never contain a
colon, so it is possible to specify a disk that has an equal
sign in its name using the storage specification
dm:disk01=a. Without the dm: prefix, disk01=a would yield
an error indicating an unrecognized attribute.
Defined attributes (and common aliases) are:
alloc=storage-spec[,storage-spec,...]
This is provided as an alternate syntax for speci-
fying storage as single attributes. It is useful
in a defaults file, so that all attributes
(including storage specifications) will be in the
attribute=value format. Any number of storage
specifications can be specified, separated by com-
mas. More than one alloc attribute can be speci-
fied, in which case they are logically con-
catenated to form one longer list.
comment=comment
Specify a comment to give to a volume when it is
created. This comment can be displayed with
vxprint -l, and can be changed, at a later time,
with vxedit set. This attribute is used only with
the make operation.
diskgroup=disk-group (alias: dg)
Specify the disk group for an operation. If a
disk group is specified in a defaults file, then
it just specifies the default disk group to use
for the make operation, if no other means of
determining the disk group can be used. If speci-
fied as a command line attribute, it has the same
effect as specifying a disk group with the -g
option (the operation is forced to apply to the
given disk group).
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excl=yes|y|on|true|no|n|off|false
Sets or clears the EXCLUSIVE flag on the volume.
A volume in exclusive open state can be opened by
only one node in the cluster at a time. Multiple
opens of an exclusive volume from the same node
are permitted. Non-exclusive volumes can be
simultaneously opened by more than one node.
After a node opens an exclusive volume, every
other node's open attempt fails until the last
close of the volume by the first opener. Such an
open failure returns a EBUSY error code. Avail-
able only with Cluster Volume Manager.
fstype=file-system-type
Specify the file system type for a new volume
(this is used only with the make operation). The
file system type for a volume is usually deter-
mined when needed by running the fstyp utility
(see fstyp(1M)), but can be specified explicitly.
The file system type parameter is used with the
Volume Manager vxresize utility, as well as with
volume snapshots, copies, and dissociates (to
select features that are used with the VERITAS
VxFS file system).
The file system type can be changed at any later
time with the vxedit set operation.
group=owning-group
Set the group ID for a new volume. The group ID
can be specified numerically or with a system
group name. This attribute is used only with the
make operation. By default, volumes are created
with group 0.
init=initialization-type
Specify the means for initializing a new volume.
The default method (which can be selected expli-
citly with init=default) is to call vxvol start to
do a usage-type-specific default initialization
operation. A new volume can be left uninitialized
with init=none. The most useful non-default ini-
tialization that can be specified is init=zero, to
clear the volume before enabling it for general
use.
layout=layout-spec[,layout-spec,...]
Specify a volume or plex layout type (RAID-5, mir-
rored, unmirrored, striped, cylinder alignment),
and turn on or off some features (such as log-
ging). The list of layout specifications is given
in the next section. By default, unmirrored,
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non-striped volumes are created with no log.
loglen=length
Specify a log length to use for dirty-region log
subdisks for mirrored volumes or for RAID-5 log
plexes. If a log length is specified on the com-
mand line, then logging will be enabled by
default.
logtype=drl|region|none
Specify the logging type for a mirrored volume.
Dirty region logging (the default) can be selected
with either logtype=drl or logtype=region. Log-
ging can be disabled altogether with logtype=none.
max_nraid5column=number
(alias: maxraid5columns, max_nraidcolumn,
max_nraid5stripe, max_nraidstripe, maxraidcolumns,
maxraid5stripes, maxraidstripes) Specify the
default maximum number of stripe columns for a
RAID-5 volume (default value is 8). The rules for
selecting the default number of RAID-5 stripe
columns are described in the nstripe attribute.
max_ncolumn=number (alias: maxcolumns, max_nstripe, maxstripes)
Specify the default maximum number of stripe
columns, either for a RAID-5 volume (if
max_nraid5stripe is not also specified) or for a
striped plex (default value is 8). The rules for
selecting the default number of stripe columns is
described in the nstripe attribute.
max_regionloglen=length (alias: maxregionloglen)
Specify the maximum default dirty region logging
log subdisk length. If the user does not specify
the dirty region log length for a volume, when
creating the first log for a mirrored volume,
vxassist uses a simple formula based on the log
length. The default length will not be bounded by
max_regionloglen (default value is 32K).
min_nraid5column=number
(alias: minraid5columns min_nraidcolumn,
min_nraid5stripe, min_nraidstripe, minraidcolumns,
minraid5stripes, minraidstripes) Specify the
default minimum number of stripe columns for a
RAID-5 volume (default value is 3). The policy
for selecting a default number of RAID-5 stripe
columns will not be allowed to create a RAID-5
volume with fewer than min_nraid5stripe stripe
columns.
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min_nstripe=number (alias: minstripes)
Specify the default minimum number of stripe
columns for either a RAID-5 volume (if
min_nraid5stripe is not also specified) or for a
striped plex (default value is 2). The policy for
selecting a default number of stripe columns will
not be allowed to select fewer than this number of
columns.
mirror= +/- number|yes|no|diskclass[,...]
Specify various mirroring parameters. Multiple
mirroring parameters can be given, each separated
by a comma. A decimal number indicates a specific
number of mirrors to create, when creating a mir-
rored volume (equivalent to nmirror=number). yes
indicates that volumes should be mirrored by
default (equivalent to layout=mirror). no indi-
cates that volumes should be unmirrored by default
(equivalent to layout=nomirror).
Any other mirroring parameters specify that
volumes should be mirrored across instances of a
particular disk class. For example, mirror=target
specifies that volumes should be mirrored between
SCSI target addresses. Each mirror can contain
disks from any number of instances of the disk
class, but different mirrors cannot use disks from
the same instance of the disk class.
mode=permissions
Specify the permissions for the block and charac-
ter device nodes created for a new volume. The
mode can be specified either as an octal number or
symbolically. A symbolic mode is specified using
the syntax given in chmod(1). This attribute is
used only with the make operation. The default
mode for a volume gives read and write access only
to the owner.
nlog= +/- number, (nlogs, logs)
Specify the number of logs to create, by default,
for a RAID-5 or mirrored volume (presuming that
logs will be created). The number of logs to
create can be specified independently for RAID-5
or mirrored volumes using the nraid5log and nre-
gionlog attributes.
nmirror= +/- number, (nmirrors, mirrors)
Specify the number of mirrors to create when mir-
roring a volume (default value is 2).
nraid5log=number
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(alias: nraid5logs, raid5logs, nraidlog, nraid-
logs, raidlogs) Specify the number of log plexes
to create for a new RAID-5 volume (default value
is 1). This attribute is used only with the make
operation.
nraid5stripe= +/- number
(alias: raid5stripes, nraid5column, nraidstripe,
raidstripes, raidcolumns, nraidcolumn,
raid5columns) Specify the number of stripe columns
to use when creating a new RAID-5 volume (the
default is to adjust the number to available
disks). This attribute is used only with make and
relayout operations. For the relayout operation,
the default is the same number of stripe columns
the volume has. For the relayout, this value can
be preceded by a + or a - in order to add or sub-
stract column(s).
nregionlog=number (alias: nregionlogs, regionlogs, ndrl)
Specify the number of log subdisks to create for a
new mirrored volume (default value 1). This
attribute is used only with the make operation,
and only if logging is requested for the volume.
nstripe= +/- number
(alias: stripes, ncolumn, ncolumns, ncol, ncols,
columns, cols) Specify the number of stripe
columns to use when creating a new RAID-5 volume
(with the make operation) or when creating a
striped plex (with the make, relayout, mirror, and
snapstart operations). The default is to adjust
to the number of available disks. For the relayout
operation, the default is the same number of
stripe columns the volume has. For the relayout,
this value can be preceded by a + or a - in order
to add or substract column(s).
raid5_stripeunit=width
(alias: raid5_stwidth, raid5_st_width,
raid5_stwidth, raid_st_width, raid_stripeunitsize,
raid5_stripeunitsize, raid5_stripeunitwidth,
raid_stwid, raid_stwidth, raid_stripeunit,
raid_stripeunitwidth) Specify the stripe unit size
to use when creating a new RAID-5 volume (default
value is 16K). This attribute is used only with
the make operation.
raid5loglen=length, (alias: raidloglen)
Specify the log length to use when adding the
first log to a RAID-5 volume. The default is four
times the full stripe width (the stripe unit size
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times the number of stripe columns).
regionloglen=length, (alias: drlloglen, drllen)
Specify the log subdisk length to use when adding
the first log subdisk to a mirrored volume. The
default is chosen based on a formula involving the
volume length.
stripe=diskclass[,...]
Specify that volumes should be striped across
instances of a particular disk class. For exam-
ple, stripe=target specifies that volumes should
be striped between SCSI target addresses. Each
column can contain disks from any number of
instances of the disk class, but different columns
cannot use disks from the same instance of the
disk class.
stripe_mirror_col_trigger_pt=size
This size specification triggers the creation of a
stripe-mirror volume. If the size of the volume
is greater than the size specified in this attri-
bute, then a stripe-mirror volume is created.
stripe_mirror_col_split_trigger_pt=size
This size specification triggers the creation of a
stripe-mirror-sd volume. If the size of each
column is greater than the size specified in this
attribute, then a stripe-mirror-sd volume is
created.
stripe_stripeunit=width
(alias: stripe_stwid, stripe_stwidth,
stripe_st_width, stripe_stripeunitsize,
stripe_stripeunitwidth) Specify the stripe unit
size to use when creating striped plexes to attach
to a volume. When attaching a new plex, the
default is to use the same stripe unit size as any
other striped plexes in the volume. If the volume
does not yet contain striped plexes, the default
value is 64K.
stripeunit=width
(alias: stwid, stripewidth, stwidth, st_width,
stripe_width, stripeunitsize, stripeunitwidth)
Specify the stripe unit size to use for either a
RAID-5 volume or for striped plexes. stripeunit
can be used to set the values for both
raid5_stripeunit and stripe_stripeunit.
tmpsize=size
Specify the space to be used as temporary storage
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in order to perform a relayout operation.
tmpalloc=storage-spec[,storage-spec,...]
Specify a set of desired storage specifications
for the temporary storage required during a relay-
out operation. The format is the same as for the
alloc attribute (a comma-separated list of storage
specifications).
user=owning-user
Specify the user ID for a new volume (default
value is root). The user ID can be specified
numerically or it can be a system login name.
This attribute is used only with the make opera-
tion.
usetype=volume-usage-type
Specify the usage type to use when creating a new
volume (default value is raid5 for RAID-5 volumes;
fsgen, otherwise). This attribute is used only
with the make operation. The usage type can also
be specified in the option list with -U.
wantalloc=storage-spec[,storage-spec,...]
Specify a set of desired storage specifications.
This is useful in a defaults file to indicate
desired storage specifications that should be dis-
carded if they fail to yield a reasonable set of
allocations. The format is the same as for the
alloc attribute (a comma-separated list of storage
specifications).
For example, a defaults file can name a specific
controller type to use for allocations, if possi-
ble. As soon as all disks on that type of con-
troller are full, other controllers will be used.
wantmirror=diskclass[,diskclass,...]
Specify a desired list of disk class mirroring
specifications. This is useful in a defaults file
to indicate a set of desired mirroring constraints
that can be dropped if they fail to yield a rea-
sonable set of allocations.
For example, a defaults file can specify that
volumes should be mirrored between disks on dif-
ferent controllers in the system. Then, if the
set of volumes builds up in such a way that a new
volume cannot be mirrored across SPARCstorage
Array trays, this constraint will be dropped.
wantstripe=diskclass[,diskclass,...]
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Specify a desired list of disk class stripping
specifications. This is useful in a defaults file
to indicate a set of desired stripping constraints
that can be dropped if they fail to yield a rea-
sonable set of allocations.
For example, a defaults file can specify that
volumes should be striped between disks on dif-
ferent controllers in the system. Then, if the set
of volumes builds up in such a way that a new
volume cannot be striped across SPARCstorage Array
trays, this constraint will be dropped.
Layout Specifications
The layout attribute specifies a comma-separated list of
simple parameters (with no arguments) that apply to vxassist
operations.
Two new layouts were added in the 3.0 release of Volume
Manager: stripe-mirror and concat-mirror. In previous
releases, whenever mirroring was used, the mirroring had to
happen above striping or concatenation. Now there can be
mirroring both above and below striping and concatenation.
Putting mirroring below striping mirrors each column of the
stripe. If the stripe is large enough to have multiple sub-
disks per column, each subdisk can be individually mirrored.
A similar concatenated volume would also mirror each subdisk
individually. These new layouts enhance redundancy and
reduce recovery time in case of an error. In a mirror-
stripe layout, if a disk fails, the entire plex is detached,
thereby losing redundancy on the entire volume. When the
disk is replaced, the entire plex must be brought up to
date. Recovering the entire plex can take a substantial
amount of time. If a disk fails in a stripe-mirror layout,
only the failing subdisk must be detached, and only that
portion of the volume loses redundancy. When the disk is
replaced, only a portion of the volume needs to be
recovered.
The new volume layouts are more complex than the older
volume layouts. Because the advantages of recovery time and
improved redundancy are more important for larger volumes,
it is best to continue using mirror-stripe and mirror-concat
for most volumes and only use stripe-mirror and concat-
mirror for very large volumes.
You can specify layout=mirror-stripe or layout=stripe-mirror
to implement the desired layout. If you specify
layout=mirror-stripe, vxassist automatically determines the
best layout for the volume. Unless there is a reason to
implement a particular layout, it is best to let vxassist
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create the layout for each volume. Because the advantages
of the new layouts are related to the size of the volume,
vxassist creates the simplest configuration for smaller
volumes and the more complex stripe-mirror for larger
volumes.
The attributes stripe_mirror_col_trigger_pt and
stripe_mirror_col_split_trigger_pt control the selection.
They can be set in /etc/default/vxassist. Volumes that are
smaller than stripe_mirror_col_trigger_pt are created as
mirror-stripe, and volumes that are larger are created as
stripe-mirror. If vxassist creates the stripe-mirror and
the columns are larger than
stripe_mirror_col_split_trigger_pt, the individual subdisks
are mirrored instead of mirroring the columns of the stripe.
By default, both of these attributes are set to one giga-
byte.
The diskgroup must be created on a 3.0 or later release to
use the new layouts, but older diskgroups can be updated.
See the vxdg upgrade command for more information on upgrad-
ing diskgroups.
Defined layout specifications are:
mirror, nomirror, raid5
New volumes should be mirrored, unmirrored
(default), or RAID-5, respectively. For mirror,
The attributes stripe_mirror_col_trigger_pt and
stripe_mirror_col_split_trigger_pt are applied.
mirror-stripe
New volumes should be mirrored and striped. The
mirroring is done at the volume level. The attri-
butes stripe_mirror_col_trigger_pt and
stripe_mirror_col_split_trigger_pt are ignored
with this layout.
mirror-concat
New volumes should be mirrored. The mirroring is
done at the volume level. The attributes
stripe_mirror_col_trigger_pt and
stripe_mirror_col_split_trigger_pt are ignored
with this layout.
stripe, nostripe
New plexes should be striped or unstriped, respec-
tively. When creating a new volume, the default
is nostripe. When adding a new plex to an exist-
ing volume, the default is stripe if the volume
already has one or more striped plexes, and nos-
tripe in other cases. For stripe (when combined
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with mirror, The attributes
stripe_mirror_col_trigger_pt and
stripe_mirror_col_split_trigger_pt are applied.
stripe-mirror
New volumes should be striped and mirrored. The
mirroring is handled at each column level or sub-
disk level depending on the attribute
stripe_mirror_col_split_trigger_pt.
stripe-mirror-col
New volumes should be striped and mirrored. The
mirroring is handled at each column level. The
attributes stripe_mirror_col_trigger_pt and
stripe_mirror_col_split_trigger_pt are ignored
with this layout.
stripe-mirror-sd
New volumes should be striped and mirrored. The
mirroring is handled at each a subdisk level.
concat-mirror
New volumes should be concatenated and mirrored.
The mirroring is handled at each a subdisk level.
The attribute stripe_mirror_col_split_trigger_pt
is applied.
span, nospan
Allow (default) or disallow plexes, regular stripe
columns, or RAID-5 stripe columns from spanning
multiple disks. If nospan is indicated, then
plexes or columns can be formed from multiple
regions of the same disk, but cannot be formed
from more than one disk.
contig, nocontig
Disallow or allow (default) plexes, regular stripe
columns, or RAID-5 stripe columns from using mul-
tiple regions of disk. If contig is specified,
then plexes and columns must be allocated from a
single contiguous region of disk. If this is not
possible, the allocation fails. By default, vxas-
sist tries to allocate space contiguously, but
will use multiple regions or multiple disks if
needed.
log, nolog
Create (or don't create) dirty region logs (for
mirrored volumes) or log plexes (for RAID-5
volumes) when creating a new volume. This attri-
bute can be specified independently for mirrored
and RAID-5 volumes with the raid5log and regionlog
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layout specifications.
grow, nogrow
Allows a volume to grow during a relayout opera-
tion.
shrink, noshrink
Allows a volume to shrink during a relayout opera-
tion.
raid5log, noraid5log
Create (default) or don't create log plexes for
RAID-5 volumes.
regionlog, noregionlog
Create or don't create (default) dirty-region log
subdisks for mirrored volumes.
diskalign, nodiskalign
Align (default) or don't align subdisks on
cylinder boundaries. When alignment is not dis-
abled, subdisks are created beginning on cylinder
boundaries and are extended to match the end of a
cylinder. Dirty region log subdisks, however, are
not cylinder aligned (they are usually only 2 or 3
blocks long). Instead, when creating log sub-
disks, spaces are located from the available disks
that could not be turned into regular subdisks
because the spaces aren't cylinder aligned. For
example, once one cylinder is used for a log sub-
disk, that cylinder cannot be used to create an
aligned data (or RAID-5 log) subdisk, so other log
subdisks will be created there until that cylinder
fills up.
FILES
/etc/default/vxassist System default settings file
for vxassist attributes.
EXIT CODES
The vxassist utility exits with a nonzero status if the
attempted operation fails. A nonzero exit code is not a
complete indicator of the problems encountered, but rather
denotes the first condition that prevented further execution
of the utility.
See vxintro(1M) for a list of standard exit codes.
SEE ALSO
chmod(1), fstyp(1M), sync(1M), vxedit(1M), vxintro(1M),
vxmake(1M), vxmend(1M), vxplex(1M), vxrelayout(1M),
vxresize(1M), vxsd(1M), vxtask(1M), vxvol(1M)
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